I would not worry about acne on this supplement. On the contrary, Powerful actually improves my skin tone, and it seems my acne clears up when I am dosing it. My nails grow kind of fast, but on Powerful, they seem to grow even faster. It's kind of weird.
I think it is best to take it on a semi-empty stomach prior to bed and about an hour before meals. Eat a high protein, low carb meal for your last meal of they day to maximize the potential for growth hormone release at night. Carbs increase insulin, and increased insulin hampers growth hormone. Someone correct me if I am wrong.
It is inevitable that someone will post that this supplement is bogus. But from my experience, I have had good results with it.